Fluxing blast-furnaces



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Patented Feb. 12, 1856.

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CHRISTIAN SHUNK, OF SLATE LICK, PENNSYLVANIA.

FLUXING BLAST-FURNACES.

Specification forming part of Letters'latent No. 14,257, dated February'12, 1856 Reissued May 31,

To all whom it may concern:

Be it known that I, CHRISTIAN SHUNK, of Slate Lick, in the county of Armstrong, State of Pennsylvania, have invent-ed a certain new and useful improvement in fluxing blast-furnaces in the manufacturing of pig and cast iron in the common blast-furnace, where coke and stone-coal are used as a fuel, and do hereby declare that the following is a clear and exact description thereof, reference being had to the annexed specifications and drawings.

My improvement is designed to be applied to the manufacturing of pig iron in the blast furnace, where stone coal and coke are used as a fuel, and consists in the mode hereinafter described of using a flux of common salt, (chlorid of sodium) by introducing it immediately into the body of the furnace, at or near the twyer, instead of at the top of the stack or tunnel head, as is now practised in the common way of fluxing blast furnaces.

I am aware that the use of salt has been suggested before, and that its use has been attempted, but as far as I am informed, it has never been brought into practical'use, owing to the fact that when used by introducing it at the top of the stack or tunnel head it immediately comes in contact with the external flame of the furnace, and at once escapes into the air, and is consumed without exerting its chemical action, as a flux, in the body of the furnace. The removal of this difficulty and the rendering the use of this excellent flux, practicable and advantageous, are the objects obtained by my invention. To every charge of ore and coal introduced at the tunnel head, I use from four to six quarts of the salt. This flux is not applied to the ore and coal at the top of the stack or tunnel head, for the reasons before stated, but is introduced at once into the hottest part of the melting mass in the furnace, where instead of being destroyed by the external flame it unites at once with the ore and coal where the chemical action is going on in the body of the furnace and exerts its chemical action in fluxing, and chiefly, it is believed, in extricating sulfur existing in the body of the furnace. I will also state that this mode of fluxing blast furnaces is useful where charcoal is used as a fuel, where sulfur exists in the iron ore used in the manufacturlng of pig metal. I find it most convenient to introduce this flux through the ordinary twyer pipe. It may however be applied through another opening, where the heat is sufiicient, below the tunnel head. I will now proceed to describe the apparatus I use for this purpose.

In the drawing Figure 1 represents a plain longitudinal section of the end of the pipe leading from the bellows or blast, and fiuxing box and twyerpipe, Fig. 2 is a perspective view of the same.

In both figures like letters of reference designate similar parts.

a is the extremity of the pipe leading from the bellows or blast. In ordinary furnaces this pipe connects immediately with the twyer pipe I), but I introduce a fiuxing box 0 of the shape shown in Fig. 2. The pipe a is inserted in the fluxing box 0 at its broadest end. This box is an air tight chamber; inside of it and in front of the pipe at is an apron a inclining from the pipe. This apron affords a pressure for the blast to force through, by which means the salt is carried by the force of the blast into the furnace twyer, where it at once unites with the separating materials in the body of the furnace. On the upper side of the fluxing box is a valve or door 6 which is used to introduce the salt and then immediately closed. A small window of mica f is placed on the end of the fiuxing box, which commands a View of the inside of the furnace. The effect of common salt when thus introduced immediately into the melting mass as a flux in the manufacturing of pig iron is to increase the heat, and produce a greater yield of met-a1, and by its chemical afiinity it probably detaches the sulfur and other deleterious substances from the materials in the furnace, which is its greatest advantage. It also preserves bright and liquid twyers, and by creating a glazing on the hearth and inside lining of the furnace, increasing greatly their durability.

I do not confine myself to any one particular shape of the fluxing box. Any

shape or size that will afford a sufiicient pressure of blast to discharge the fiux into as a flux or solvent, or its equivalent, into 10 the furnace Wlll answer the desired end, blast furnaces at the twyer, or any point Whether a box trunk or pipe. below the tunnel head in the manner and I do not claim originalifty in the use of for the purposes described. 5 common salt in treating 0 iron; but

\Vhat I do claim as my improvement and CHRISTIAN SHUNK' invention and desire to secure by Letters Signed in presence of- Patent is DANIEL MoCooK,

Applying and introducing common salt J. D. CLARK.

[FIRST PRINTED 1912.] 

